To add to what Conley had to say...

Actually the sst guns should be somewhat more durable than the blue guns. Once the sst guns were introduced pretty much all R&D went into that line. A specific heat treat sequence was developed to facilitate both manufacturing and anti-galling. Once that was accomplished there was actually more likelihood of galling the top of bbl/slide lug surfaces on a blue gun than an sst gun.

The sst used was a standard aircraft grade steel, still in common use today for aircraft - and guns. Afaik this was the first common use in firearms. So, no, it's NOT inferior to later steels (:

One early sst gun was lightly lubed with Break Free, shot ~50 rds, then wiped clean and dry (no solvent used). The gun was then used as a test bed for extractor, recoil spring, and magazine development for at least another 1500 rds - with no cleaning or lubrication other than occasional wiping of powder
residues with a dry cloth. NO galling was ever produced, and the gun ran like a top.

Re recoil springs: afair the above gun used the same recoil spring set (3 springs) the entire time, with no noticeable degredation in performance.

It's doubtful you'll ever be able to shoot enough through one of the sst pistols to ever think it feels "worn". Maybe if you're constantly practicing/competing in USPSA or IDPA...

Magazines:
- The earliest mags, made by an LA vendor, were polished sst, and were, to be charitable, "variable" in quality. The required a lot of hand fitting to ensure that they functioned properly. However, if properly set up they could be very reliable.
- The next series, made locally under Detonics control, are a matte finish (tumbled media) sst spring steel; virtually indestructible, better design (small details, tolerances), and much more reliable.

I don't at the moment recall the floorplate markings of either of these, but I'll get around to checking one of these days :)